Structure of the OmpA-like domain of RmpM from Neisseria meningitidis

Mol Microbiol. 2004 Feb;51(4):1027-37. doi: 10.1111/j.1365-2958.2003.03903.x.


RmpM is a putative peptidoglycan binding protein from Neisseria meningitidis that has been shown to interact with integral outer membrane proteins such as porins and TonB-dependent transporters. Here we report the 1.9 A crystal structure of the C-terminal domain of RmpM. The 150-residue domain adopts a betaalphabetaalphabetabeta fold, as first identified in Bacillus subtilis chorismate mutase. The C-terminal RmpM domain is homologous to the periplasmic, C-terminal domain of Escherichia coli OmpA; these domains are thought to be responsible for non-covalent interactions with peptidoglycan. From the structure of the OmpA-like domain of RmpM, we suggest a putative peptidoglycan binding site and identify residues that may be essential for binding. Both the crystal structure and solution experiments indicate that RmpM may exist as a dimer. This would promote more efficient peptidoglycan binding, by allowing RmpM to interact simultaneously with two glycan chains through its C-terminal, OmpA-like binding domain, while its (structurally uncharacterized) N-terminal domain could stabilize oligomers of porins and TonB-dependent transporters in the outer membrane.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial / chemistry*
  • Bacillus subtilis / enzymology
  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Proteins / chemistry
  • Binding Sites
  • Chorismate Mutase / chemistry
  • Crystallography, X-Ray
  • Dimerization
  • Escherichia coli Proteins*
  • Membrane Transport Proteins / chemistry
  • Models, Molecular
  • Molecular Sequence Data
  • Neisseria meningitidis / chemistry*
  • Peptidoglycan / metabolism
  • Porins / chemistry
  • Protein Binding
  • Protein Structure, Tertiary*
  • Protein Subunits
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Structural Homology, Protein


  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Escherichia coli Proteins
  • Membrane Transport Proteins
  • Peptidoglycan
  • Porins
  • Protein Subunits
  • RmpM protein, Neisseria
  • OMPA outer membrane proteins
  • Chorismate Mutase

Associated data

  • PDB/1R1M